This invention relates to improvements in construction of an electromagnetic relay installed in an automobile or the like.
According to a prior art electromagnetic relay, a magnetic circuit included therein consists of a core, a yoke, and a movable iron piece serving as an armature plate. It is intended that the armature plate be attracted due to a magnetic flux produced in a coil wound around a core. In this case, an electric current path consists of a point holder serving as a terminal, contacts caulked in or welded to the point holder, an armature spring serving as a return spring, and contacts caulked in or welded to the armature spring. A cover used for the relay is made of an iron, resin or the like.
Meanwhile, there has been a demand that a relay of this type be assembled to various parts in varying directions, so that difficulty is confronted with an automatic mechanical assembly of the relay. A magnetic flux produced by an electromagnetic coil portion passes through a yoke of an `L` shape. In this case, however, the relay suffers from considerable leakage of a magnetic flux passing through portions other than the yoke, and hence a lowered efficiency. Still furthermore, a ratio of an unoccupied space to the entire volume of a relay is considerably large, thus resulting in an increase in size of a relay as well as difficulty in reducing its weight. In addition, because of a large ratio of an unoccupied space to the volume of a relay, there arises a danger of dust being introduced into an unoccupied space, upon assembly, thus leading to a defective contacting condition of contacts and hence to unsatisfactory quality.